Antibacterials kill or inhibit the growth of bacteria by interfering with major processes of cellular function that are essential for survival. The development of antibacterial agents has significantly reduced the morbidity and mortality associated with bacterial infections over the last century, particularly in developed countries. However, the emergence of drug-resistant bacterial strains threatens the resurgence of bacterial-borne diseases long thought to have been conquered.
Resistance to antibacterials can occur when the target of a drug mutates so that it can still function, but is no longer inhibited by the drug (e.g., mutations in the quinolone resistance determining regions of bacterial gyrases and topisomerase enzymes that confer resistance to the fluoroquinolones). In a recent congressional report, the General Accounting Office (GAO) has summarized the current and future public health burden resulting from drug-resistant bacteria (Antimicrobial Resistance (1999). General Accounting Office (GAO/RCED-99-132)). According to this report, the number of patients treated in a hospital setting for an infection with drug-resistant bacteria has doubled from 1994 to 1996 and again almost doubled from 1996 to 1997. The same GAO report also provides clear evidence that previously susceptible bacteria are increasingly becoming resistant and spreading around the world. As a consequence of the increase and prevalence of resistant bacteria there is a growing need to identify new antibacterial agents.